Regulars devs don't need an excuse, they have a good reason: their optimization targets are different. The people that turn their work into their salary, and mostly the people who buy into those software, don't go away because of how large the thing is, so, why sacrifice other goals, to further this particular goal?

"If demosceners can do it" is not a good argument to talk about software, because demosceners are the cream of the software crop, when it comes to the specific thing that the demoscene is all about. It's like saying if racers can make that corner doing a 100, regular drivers have no excuse. Or I'm greatly misunderstanding your point.

Filepilot looks great. I wouldn't pay, as Double Commander serves me just fine, but an 1.8 MB download is impressive. DC is 10 MB in comparison. Still perfectly fine.